Studies of existence are terms witch metaphysics intended to discover and define them. Throughout the history of metaphysics, all philosophers have held that the subject matter of philosophy is existence, namely, the being, and regarded it us the focal point of their discussions. Among them, two have placed greater emphasis on the question of existence, and argued that philosophers have since formed on the existent, not existence, hence inadvertently ignoring the latter. Mulla Sadra and Martin Heideaer have come up with brand new insights about existence. This study is concerned with a study of their views